Rules For Fourth Species of Strict Counterpoint in Two Parts.
In the Fourth Species two notes of C.P. are written to each note of the C. F., but the first note in every measure may be a Dissonant, provided it is tied from a Consonant at the end of the preceding measure. This is called Suspension, and a C.P. of this species is called Syncopated C.P.; the Consonant, at the end of the measure is called the Preparation; the tied Dissonant, the Suspension; and the Consonant to which the dissonant moves is the Resolution; thus:1. the preparation
2. the suspension
3. the resolution
I. Any consonant may be used to prepare a dissonant, with one exception, viz., the wighth may not be used to prepare the ninth, becausee, if the tie is omitted, parallel octaves will result.
II. All suspended dissonances resolve by descending one degree.
III. When the C.P. is above the C.F. the Fourth, Seventh, and Ninth may be suspended. When the C.P. is below the C.R., the Second is the only dissonance that may be suspended.
It will be seen that the suspended fourth resolves on the third; the suspended seventh on the sixth; the suspended ninth on the eighth; the suspended second on the third.
Students are sometimes puzzled by the apparent identity of the ninth and second (when the second is moved down an octave). It is only necessary to remember that with the ninth it is the upper note that is tied; with the second, the lower note that is tied.
IV. When the tie will not produce a dissonance, it may be used or omitted at will; but it is better to use it for the sake of maintaining the syncopated effect. Then, the tied note being consonant, it may be left by motion in either direction, or by a leap to another consonant.
- Tied note, a sixth, descends.
- Tied note, a fifth, ascends.
- Tied note, a fifth, falls a third.
- Tied note, a third, rises a fourth.
When the C.P. is above it should end as follows:
Example with C.P. above.
When the C.P. is below, end thus:
Passages like the following must be avoided, because, in Example 1, parallel octaves will be formed if the ties are omitted, and in Example 2, parallel fifths, if the ties are omitted.
Violations of No. 1, will frequently be found, in fact, many authors make no objections to it.
The following passages, Nos 3 and 4 may be used, although they closely resemble No. 2.
A possible explanation may be found in the fact that No. 2 is founded on the follwoing impossible sequence:
Whereas Nos. 3 and 4 are founded on the following agreeable sequence, (No. 3 beginning with the first, and No. 4 with the second chord, thus changing the accent):
Example with C.P. above: